The monoalkyl cyclododecadienecarboxylates are useful generally as organic intermediates, and particularly after reduction of both double bonds, as intermediates in the preparation of lauryl lactam, a useful precursor to Nylon-12. Nylon-12 is a polyamide having excellent mechanical properties such as hardness, tensile strength, resistance to abrasion combined with low sensitivity toward water and low density. Present applications include coatings for cables and textiles and mouldings for automobiles. One contemplated route to Nylon-12,* starting from 1,5,9-cyclododecatriene, is to first carboxylate said triene in the presence of a suitable homogeneous, ligand-stabilized, platinum(II) or palladium(II)-Group IVB metal halide catalyst to form the monoalkyl 4,8-cyclododecadiene-1-carboxylate ester derivative by the addition of carbon monoxide and a lower alkanol (See Step 1), and then by replacing the CO atmosphere by hydrogen, and optionally using the same homogeneous catalyst, to reduce said monoalkyl unsaturated 4,8-cyclododecadiene-1-carboxylate ester to the monoalkyl ester of cyclododecanecarboxylate (See Step 2). After separating the catalyst, the cyclododecanecarboxylate ester is converted to lauryl lactam by treatment with nitrosylsulphuric acid (Step 3). Polymerization of lauryl lactam yields the polyamide known as Nylon-12 (Step 4). FNT *See K. Bittler et al., Angew.Chem.intemat.Ed., 7,329(1968) ##SPC1##